Laminated wall board



Nov. 4, 1930.

P. W. CODWISE LAMINATEDWA'LL BOARD Original Filed Feb. 23, 1928 INVENTOR I PfiM/p l/V. foam mic BY WW) a/l/zlq m gggg rmmr w.'oonwisE, OF-KENMORE, Nnw Yo advantage. as

Patented Nov. 4, 1930 UNITED STATES PATENT: orrics BK, ASSIGNOR TO CERTAIN-DEED PRODUCTS CORPORATION, OF NEW YORK, N. Y., CORPORATION OF MARYLAND I LAMINATED WALL BoA m Original annlioation filed February 23,

1928, Serial No. 256,091; Divided and this application filed June 13, 1928. Serial No. 284,962.

.An object of the present invention is the production of a thick laminated board, .the outer plies of which are formed, for the most part, of wood screenings and saw-dust and the inner plies of which are formed, at least in part, frompaper waste. A further object is to provide a wall board of this character havin such strength, toughness and freedomrom warpage and having such good insulating qualities, that it can be used with a plas r base on which to apply stucco and a hard finish.

. This new product is obtained by a novel process. Other objects and advantages of the present invention will become appar-- ent-from the following description taken n conjunction with the accompanying draw- 1 is a diagrammatic representation of one of the layers of which the board is built, the plies of the layer being separated in the drawing to show their 1 relation to each other, and

Fig. 2 is a perspective view ,of' a fragment of the complete board. 3 As described and claimed in .my paren application, the complete board, asillustrated in Fig. 2 of the drawin s, comprises several separate layers, pre erably five, cemented together with a suitable adhesive.

- When the board is made according to the 35 embodiment of the invention forming the subject matter of the present irfvention, each layer is about .08 inches in thickness and possesses the characteristics of. an'extreme rough surface. The five or more layers are identical in construction and each of. them preferably consists of six plies felted together during the process of manufacture. The four outermost plies, reference numerale 1, 2, 3 and 4, see Fig. 1, are composed torn apart when the spruce log is ground to pulp on the grind stone. While the propor tions of materials employed in the manu-. facture of the outer plies may be varied,

1} preferably employ approximately equal parts of ground wood screenings and sawdust. t

By using screenings as a major of the two outer-most plies of each layer,

constituent the layer is given a nap or roughened surface of substantial advantage when the layers are being cemented together and also a great importance in securing a firm bond between the board and a layer of plaster spread thereon when the board is with suchscreenings in proper proportions qa an increased rbulk is-obtained without sacrificing these advantages. The two innermost plies 5"'an d 6 can well contain a relatively high percentage of short fibered stock. T

The short fibered stock for the inner plies "5 and 6 is madeby charging the ingredients into 'a hollander' heater and there beating on a continuous plan until a smooth, uniform pulp is produced. inner plies may vary but I have found that wood flour,

a'mixture of substantially 35% 30% ground wood and 35% mixed paper gives excellent results. Newspaper waste,

container board waste -and the like can be all it takes about used.. Roughly estimated,

to pass such a threeequarters of an hour charge through sizing of the short fibered-stock is important used as the inner wall of a 5 building. The addition of saw-dust tdthe mg the four outermost 7o The ingredients of the the hollanden A suitable 1 5O ly' of slivers,

and I prefer to effect this sizing with an alum 95.

rosin.size,.introducing thealum to the extent of 4% by dry weight into the batch while in the hollander and introducing thesolution of rosin-at the head box just before the stock.

passes to the Jordan, using rosin .to the exessentially of ground wood screenings, wood flour and saw-dust. The ..screenings-. are preferably spruce screenings obtained-from ground wood pulp in usual paper making operations. Such screenings consist largeshives or bundles of fibers, not

tent of 3% by dry weight. From the hollander beater the short fibered stock passes to a beater chest, then to the Jordan, then to the machine chest andthen to two of the cylinders of a six cylinder machine as hereinafter described. Each of these plies has a thickness of about .011". This short fibered stock thus sized is pressed as it leaves these two cylinders for felting between the'four outer plies of stock.

In the embodiment of the invention forming the sub'ect matter of this application, the stock for t e outer plies, consisting of Wood pulp screenings, preferably ground spruce, 5 Wood flour and fine saw-dust, is run into a hollander with water and alum and there beaten to a uniform pulp. The wood screenings and saw-dust may be employed 'in substantially equal parts and the shives or bundles of fibers of the screenings should average one-quarter to one-half an inch in length. From the hollander the beaten charge is run into the beater chest where a rosin solution is added to thoroughly size the fibers.

The percentages of alum and rosin may be.

- the same with this stock as with the stock ofthe inner plies. The stock is then lightly jordanned and then passed to four cylinders of the six cylinder machine. The amount of sawdust employed in the outer plies may be varied within wide limits, greater quantities being used where greater bulk is desired.

When saw-dust is used in the mixture, certain precautions are necessary during the pressing operation to prevent splitting the bond between the plies of the layer or increasing the density of the product beyond the desired limits. The press employed consists of two primary rolls and one large roll. The weight on the primary rolls is merely sufficient to keep the machine operating and in the large press, I employ a light weight,

upper roll without an leverage or additional weights on it. The sheet is thus compressed ver little and retains practically all the bul characteristics which the saw-dust naturally imparts to it. During the pressing operation excess water is removed from the plies and the constituents are bonded to each other. The plies are also felted together in an inherent sheet or layer as indicated in Fig. 1 of the drawings. The layer is then dried on drums in the usual manner but without calendering or other surface treatment which 5 would destroy the roughened or nappedsurface of the outermost plies.

After the layers have been formed, they are passed throu h a laminating machine and a suitable adhesive applied to cement them together into la rigid board. .An adhesive composed of silicate and clay has advantages for cementing the layers together. A clay silicate mixture as described in the Carter Patent, No. 1,188,040 granted June 20, 1916, is suitable, but a water compound such as lime-casein may be employed. Proper sizing. of the fibers of the plies is important at this stage of the process as the sizing regulates to some extent the penetration of the adhesiveness and its effectiveness in producing a good bond between. adjacent layers. The water content of the board is increased by the application of the adhesive and the board may then be dried by kiln drying and/or by seasoning until the moisturecontent drops to about 12 percent.

The process of the present invention has the advantage that it can be carried out with standard equipment. The beaters, J ordans, cylinder machine, drum dryers and laminating machines are Well understood by Workers in this art. Recourse need notv be had to special or expensive processes, and the like. The layers of stock each composed of a plurality of plies can be readily stored or can be transported to a remote board mill without detrimental change in moisture content and when cemented together into the complete board yield a product in which the moisture content is substantially uniform throughout.

The product of the present invention has good insulating qualities and when a large proportion'of saw-dust is used, it has great bulk in addition .to tensile strength. The laminated form of the product contributes toward greater strength and the clay silicate adhesive between the layers, not only stiflens the structure but is to some extent aprotection against fire. In addition, the provision of long fibered or sli-vered stock in the outermost plies produce a sheet with a nap or surface roughness of substantial benefit in cementingthe plies together and of controlling importance on the adhesion which can be had when the board is used as a plaster base for the inner wall of a building. Such a plaster continuous dryers base must be strong and tough, must not warp, 7

must take up enough water to make proper bond with the plaster and must not take up that water. too rapidly. The board above described fulfills all these conditions. It serves'satisfactorily asthe base for a plaster layer three-eighths to one-half inches in thickness over whichmay be applied a hard I fiiiish in the usual manner.

The board may be built of any number of layers and any number of plies may be used in the board thereby increasing the thickness of the board for various uses without essentially changing its characteristic features.

Additional plies in each layer' or additional layers in the finished board,of course; give greater strength and increase insulating power? I claim: I

1. A laminated wall board composed of a plurality of layers, eachlayer having outer plies composed in part of pulp screenings and tween the adjacent layers, each of said laya in the form of ground wood screenings and saw-dust and inner plies composed in part of paper waste. 7

2. A laminated wall board composed of a plurality of layers, each layer having outer plies composed of spruce in the form of ground wood screenings and saw-dust properly sized and inner plies composed in part at least of paper Waste.

3. A laminated .wall board composed of a plurality of layers, each layer having outer plies composed of ground wood screenings and saw-dust properly sized and having inner plies composed of about 35 percent paper waste, 35 percent woodflour and 30 percent ground wood all by dry weightand suitably sized.

4. A laminated wall board composed of a plurality of plies grouped in separate layers andjwith adhesive applied between the adjacent layers, the outer plies of each layer being composed essentially of spruce in "the form of ground wood screenings and'saw-dust suitably sized and the inner plies being composed essentially of paper waste, wood flour and ground wood suitably sized.

5. A laminated wall board comprising a plurality of plies grouped in separate layers and with a stifiening adhesive applied between adjacent layers, each of said layers having its outermost plies composed of ground wood screenings and saw-dust suitably sized and its inner plies composed in part at least of paper waste. Y

6. A laminated plaster base board comprising a plurality of plies grouped in separate layers and with adhesive applied beers having its four outermost plies composed of spruce in the form of ground wood screenings and saw-dust suitably sized and having its innermost plies composed essentiall of paper waste, ground wood and'wood our.

7. A laminated plaster base board comprising a plurality of plies grouped in separate layers and with clay silicate adhesive between adjacent layers, each of said layers having its outermost plies composed of spruce saw-dust suitably sized and having its innermost plies composed of about 35 percent paperwaste, 30 percent ground wood and 35 percent wood flour all by dry weight and suitably sized. I

8. The method which comprises beating a mixture of paper waste, wood flour and ground wood to a pulp, .shaping said pulp into plies, uniting said plies by pressure between plies of ground wood screenings and saw-dust to form a coherent layer having a rough surface substantially as described and cementing apluralit y of such layers together to form a rigidplaster base board.

- 9. The process which comprises beating into 'a pulp with water a mixture of substantially 35 percent paper waste, 35 percent wood PHILIP w. CODWISE. 

